How To Use Ansible Shell Module

Ansible is a powerful automation tool that allows you to manage and configure multiple servers simultaneously. One of the key features of Ansible is its ability to execute commands on remote servers using modules. One such module is the Ansible Shell module, which allows you to run shell commands on remote servers.

In this article, we will explore how to use the Ansible Shell module to execute shell commands on remote servers. We will cover the syntax of the Shell module, how to pass arguments to shell commands, and some best practices for using the Shell module in your Ansible playbooks.

The Ansible Shell module is used to execute shell commands on remote servers. It is a powerful tool that allows you to run complex shell commands on multiple servers at once. The syntax of the Shell module is simple and easy to understand. To use the Shell module in your Ansible playbook, you simply need to include the "shell" keyword followed by the shell command you want to execute.

For example, if you want to run the "ls -l" command on a remote server using the Shell module, your Ansible playbook would look like this:

```
- name: Run ls -l command
hosts: all
tasks:
- name: Execute ls -l command
shell: ls -l
```

In this example, we are running the "ls -l" command on all hosts specified in the playbook. The Shell module will execute the command on each host and return the output to the Ansible controller.

You can also pass arguments to shell commands using the Shell module. To do this, you simply need to include the arguments after the shell command in the playbook. For example, if you want to run the "echo" command with an argument on a remote server, your playbook would look like this:

```
- name: Run echo command
hosts: all
tasks:
- name: Execute echo command
shell: echo "Hello, World!"
```

In this example, we are running the "echo" command with the argument "Hello, World!" on all hosts specified in the playbook. The Shell module will execute the command on each host and return the output to the Ansible controller.

When using the Ansible Shell module, it is important to follow some best practices to ensure that your playbooks are efficient and secure. One best practice is to use the "become" keyword to run shell commands with elevated privileges. This is especially important when running commands that require root access on remote servers.

To use the "become" keyword with the Shell module, you simply need to include it in the playbook before the shell command. For example, if you want to run a shell command with root privileges on a remote server, your playbook would look like this:

```
- name: Run command with elevated privileges
hosts: all
tasks:
- name: Execute command with elevated privileges
become: yes
shell: command
```

In this example, we are running the "command" with elevated privileges on all hosts specified in the playbook. The Shell module will execute the command with root access on each host and return the output to the Ansible controller.

Another best practice when using the Ansible Shell module is to use variables to store shell commands. This can make your playbooks more readable and easier to maintain. To use variables with the Shell module, you simply need to define the variables at the beginning of the playbook and reference them in the tasks.

For example, if you want to run a shell command stored in a variable on a remote server, your playbook would look like this:

```
- name: Run command stored in a variable
hosts: all
vars:
my_command: ls -l
tasks:
- name: Execute command stored in a variable
shell: "{{ my_command }}"
```

In this example, we are defining a variable called "my_command" with the value "ls -l" at the beginning of the playbook. We then reference the variable in the Shell module task to execute the command on all hosts specified in the playbook.

In conclusion, the Ansible Shell module is a powerful tool that allows you to execute shell commands on remote servers. By following best practices such as using the "become" keyword and variables, you can ensure that your playbooks are efficient and secure. Start using the Ansible Shell module in your playbooks today to automate your server management tasks and streamline your workflow.